The present invention relates to an antitheft system capable of preventing an automotive vehicle from being stolen.
A conventionally known antitheft system (i.e. a security equipmet) for preventing an automotive vehicle from being stolen is arranged to receive signals from door switches detecting door open/close conditions, an ignition switch, or any other detectors provided for various purposes in an automotive vehicle and to generate an alarm by using a siren or a horn based on these signals when any unfair act of an unauthorized person to the automotive vehicle is detected, for example, when one of the doors is forcibly opened or an engine is started by an unauthorized person.
It is also known to use, in addition to such a fundamental arrangement, an ultrasonic or radio intrusion sensor for detecting any unauthorized person entering into a vehicle, a glass crack sensor for detecting a glass being broken, an inclination sensor for detecting an inclined vehicle body, an impact sensor for detecting any impact force applied on the automotive vehicle, or any other security sensor specialized to detect any unfair act of an unauthorized person to the automotive vehicle. For example, the Japanese Patent Application Laid-open No. 2003-95068 discloses a conventional system using such security sensors to detect any abnormality and generating alarm.
According to a burglar alarm unit equipped with this kind of security sensors, the burglar alarm unit can operate in an alarm set state for generating alarm, while selecting its operation mode between a security sensor ON mode and a security sensor OFF mode. The security sensor ON mode includes not only execution of alarm based on the security sensors but also execution of alarm based on the detectors other than the security sensors. The security sensor OFF mode includes prohibition of alarm based on the security sensors and execution of alarm based on only the detectors other than the security sensors.
More specifically, in general, this kind of burglar alarm unit performs an automotive door lock control, and switches its operation between an alarm set state and an alarm unset state (i.e. a condition generating no alarm) in response to lock/unlock of the door. For example, there is a specified waiting time (e.g. 30 seconds) from the locking of doors before the burglar alarm unit starts operating in the alarm set state. On the other hand, the operation mode of the burglar alarm unit is immediately switched to the alarm unset state upon unlocking the door. The burglar alarm unit also performs so-called answer back that includes a predetermined pattern of flickering by automotive hazard lamps to inform a user of execution of lock/unlock of the doors.
Furthermore, the burglar alarm unit goes into the alarm set state if a specific operation is made to invalidate the signal of the security sensor under the alarm unset state (for example, when a sensor cancel switch is turned on to deactivate the security sensor). In this case, the burglar alarm unit selects the alarm set state of security sensor OFF mode. On the contrary, the burglar alarm unit may shift into the alarm set state without responding to the above-described specific operation under the alarm unset state. In such a case, the burglar alarm unit selects the alarm set state of security sensor ON mode.
The above-described procedures are mandatory as apparent from the Japanese Safety Standards (refer to safety standards, article 43(5)—detailed notification principles—article 54—appendix 63: technical standards relating to antitheft alarm devices 4.1.1). According to this regulation, cancellation of the security sensor signal (direct switching from the security sensor ON mode to the security sensor OFF mode) is not allowed under the alann set state. The regulation requires the antitheft alarm device to once shift into the alarm unset state before establishing the alarm set state of security sensor OFF mode. Similar regulations are present in the relevant laws of Europe (95/56/EC) or United Nations (BCE97).
On the other hand, the security sensor OFF mode can be used in the following situation. For example, when an intrusion sensor is installed as a security sensor of an automotive vehicle, a user may leave his/her pet in a compartment of the vehicle while bringing the burglar alarm unit into the alarm set state. In such a case, the security sensor OFF mode is preferable in that no erroneous alarm is generated in response the pet moving around in the automotive vehicle.
Furthermore, an inclination sensor or an impact sensor can be installed as a security sensor of the automotive vehicle. In such a case, the security sensor OFF mode is preferable in that no erroneous alarm is generated during transportation of automotive vehicles by a carferry which may frequently roll on the way to a destination.
According to the above-described burglar alarm unit equipped with such security sensors, a user may choose the alarm set state of security sensor OFF mode before he/she leaves the automotive vehicle. However, at a later timing, this user may change his/her mind and want the burglar alarm unit to operate in the alarm set state of the security sensor ON mode. In such a case, the user needs to return to his/her automotive vehicle to once release the alarm set state (i.e. shift into the alarm unset state as a first step). To this end, for example, the user unlocks the door. Then, as a succeeding step required for bringing the burglar alarm unit into the alarm set state, the user locks the door.
Similarly, a user may choose the alarm set state of security sensor ON mode before he/she leaves the automotive vehicle. However, at a later timing, this user may change his/her mind to cause the burglar alarm unit to operate in the alarm set state of the security sensor OFF mode. In such a case, the user needs to return to his/her automotive vehicle to once release the alarm set state (i.e. shift into the alarm unset state as a first step). Then, as a second step required for deactivating the security sensor, a specific operation (e.g. turning on a sensor cancel switch) needs to be done by the user. Finally, as a third step, the user is required to do a necessary operation for bringing the burglar alarm unit into the alarm set state.